Low-cost sensorless control of brushless DC motors using afrequency-independent phase shifter

摘要

This paper describes a sensorless control scheme for brushless DCnmotors (BLDCMs) using a phase shifter (FlPS) which can shift thenzero-crossing point of the input signal with a specified amount ofnphase. The detection performance of the proposed FIPS is independent ofnthe frequency of the input signal and quite robust with respect to thenmeasurement noise. It is shown that the proposed sensorless controlnscheme using the FIPS is more effective in the respects ofnnoise-robustness and cost than the previously known schemes. Moreover, anflux-weakening control scheme can be easily incorporated into thenproposed sensorless control scheme. The generality and practicality ofnthe proposed sensorless control scheme is demonstrated throughnperformance analysis and experiments under various operating conditions